////////////////////////////////////////////////////////////////////////////////
// Filename: fontshaderclass.cpp
////////////////////////////////////////////////////////////////////////////////
#include "fontshaderclass.h"


FontShaderClass::FontShaderClass()
{
	m_vertexShader = 0;
	m_pixelShader = 0;
	m_layout = 0;
	m_constantBuffer = 0;
	m_sampleState = 0;
	m_pixelBuffer = 0;
}


FontShaderClass::FontShaderClass( const FontShaderClass& other )
{
}


FontShaderClass::~FontShaderClass()
{
}


bool FontShaderClass::Initialize( ID3D11Device* device, HWND hwnd )
{
	bool result;


	// Initialize the vertex and pixel shaders.
	result = InitializeShader( device, hwnd, L"../../tertut19/font.vs", L"../../tertut19/font.ps" );
	if( !result )
	{
		return false;
	}

	return true;
}


void FontShaderClass::Shutdown()
{
	// Shutdown the vertex and pixel shaders as well as the related objects.
	ShutdownShader();

	return;
}


bool FontShaderClass::Render( ID3D11DeviceContext* deviceContext, int indexCount, const XMMATRIX& worldMatrix, const XMMATRIX& viewMatrix,
	const XMMATRIX& projectionMatrix, ID3D11ShaderResourceView* texture, const XMFLOAT4& pixelColor )
{
	bool result;


	// Set the shader parameters that it will use for rendering.
	result = SetShaderParameters( deviceContext, worldMatrix, viewMatrix, projectionMatrix, texture, pixelColor );
	if( !result )
	{
		return false;
	}

	// Now render the prepared buffers with the shader.
	RenderShader( deviceContext, indexCount );

	return true;
}


bool FontShaderClass::InitializeShader( ID3D11Device* device, HWND hwnd, WCHAR* vsFilename, WCHAR* psFilename )
{
	HRESULT result;
	ID3D10Blob* errorMessage;
	ID3D10Blob* vertexShaderBuffer;
	ID3D10Blob* pixelShaderBuffer;
	D3D11_INPUT_ELEMENT_DESC polygonLayout[ 2 ];
	unsigned int numElements;
	D3D11_BUFFER_DESC constantBufferDesc;
	D3D11_SAMPLER_DESC samplerDesc;
	D3D11_BUFFER_DESC pixelBufferDesc;


	// Initialize the pointers this function will use to null.
	errorMessage = 0;
	vertexShaderBuffer = 0;
	pixelShaderBuffer = 0;

	// Compile the vertex shader code.
	result = D3DCompileFromFile( vsFilename, NULL, NULL, "FontVertexShader", "vs_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0,
		&vertexShaderBuffer, &errorMessage );
	if( FAILED( result ) )
	{
		// If the shader failed to compile it should have written something to the error message.
		if( errorMessage )
		{
			OutputShaderErrorMessage( errorMessage, hwnd, vsFilename );
		}
		// If there was  nothing in the error message then it simply could not find the shader file itself.
		else
		{
			MessageBox( hwnd, vsFilename, L"Missing Shader File", MB_OK );
		}

		return false;
	}

	// Compile the pixel shader code.
	result = D3DCompileFromFile( psFilename, NULL, NULL, "FontPixelShader", "ps_5_0", D3D10_SHADER_ENABLE_STRICTNESS, 0,
		&pixelShaderBuffer, &errorMessage );
	if( FAILED( result ) )
	{
		// If the shader failed to compile it should have written something to the error message.
		if( errorMessage )
		{
			OutputShaderErrorMessage( errorMessage, hwnd, psFilename );
		}
		// If there was  nothing in the error message then it simply could not find the file itself.
		else
		{
			MessageBox( hwnd, psFilename, L"Missing Shader File", MB_OK );
		}

		return false;
	}

	// Create the vertex shader from the buffer.
	result = device->CreateVertexShader( vertexShaderBuffer->GetBufferPointer(), vertexShaderBuffer->GetBufferSize(), NULL,
		&m_vertexShader );
	if( FAILED( result ) )
	{
		return false;
	}

	// Create the vertex shader from the buffer.
	result = device->CreatePixelShader( pixelShaderBuffer->GetBufferPointer(), pixelShaderBuffer->GetBufferSize(), NULL,
		&m_pixelShader );
	if( FAILED( result ) )
	{
		return false;
	}

	// Create the vertex input layout description.
	polygonLayout[ 0 ].SemanticName = "POSITION";
	polygonLayout[ 0 ].SemanticIndex = 0;
	polygonLayout[ 0 ].Format = DXGI_FORMAT_R32G32B32_FLOAT;
	polygonLayout[ 0 ].InputSlot = 0;
	polygonLayout[ 0 ].AlignedByteOffset = 0;
	polygonLayout[ 0 ].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
	polygonLayout[ 0 ].InstanceDataStepRate = 0;

	polygonLayout[ 1 ].SemanticName = "TEXCOORD";
	polygonLayout[ 1 ].SemanticIndex = 0;
	polygonLayout[ 1 ].Format = DXGI_FORMAT_R32G32_FLOAT;
	polygonLayout[ 1 ].InputSlot = 0;
	polygonLayout[ 1 ].AlignedByteOffset = D3D11_APPEND_ALIGNED_ELEMENT;
	polygonLayout[ 1 ].InputSlotClass = D3D11_INPUT_PER_VERTEX_DATA;
	polygonLayout[ 1 ].InstanceDataStepRate = 0;

	// Get a count of the elements in the layout.
	numElements = sizeof( polygonLayout ) / sizeof( polygonLayout[ 0 ] );

	// Create the vertex input layout.
	result = device->CreateInputLayout( polygonLayout, numElements, vertexShaderBuffer->GetBufferPointer(),
		vertexShaderBuffer->GetBufferSize(), &m_layout );
	if( FAILED( result ) )
	{
		return false;
	}

	// Release the vertex shader buffer and pixel shader buffer since they are no longer needed.
	vertexShaderBuffer->Release();
	vertexShaderBuffer = 0;

	pixelShaderBuffer->Release();
	pixelShaderBuffer = 0;

	// Setup the description of the dynamic constant buffer that is in the vertex shader.
	constantBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
	constantBufferDesc.ByteWidth = sizeof( ConstantBufferType );
	constantBufferDesc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
	constantBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
	constantBufferDesc.MiscFlags = 0;
	constantBufferDesc.StructureByteStride = 0;

	// Create the constant buffer pointer so we can access the vertex shader constant buffer from within this class.
	result = device->CreateBuffer( &constantBufferDesc, NULL, &m_constantBuffer );
	if( FAILED( result ) )
	{
		return false;
	}

	// Create a texture sampler state description.
	samplerDesc.Filter = D3D11_FILTER_MIN_MAG_MIP_LINEAR;
	samplerDesc.AddressU = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.AddressV = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.AddressW = D3D11_TEXTURE_ADDRESS_WRAP;
	samplerDesc.MipLODBias = 0.0f;
	samplerDesc.MaxAnisotropy = 1;
	samplerDesc.ComparisonFunc = D3D11_COMPARISON_ALWAYS;
	samplerDesc.BorderColor[ 0 ] = 0;
	samplerDesc.BorderColor[ 1 ] = 0;
	samplerDesc.BorderColor[ 2 ] = 0;
	samplerDesc.BorderColor[ 3 ] = 0;
	samplerDesc.MinLOD = 0;
	samplerDesc.MaxLOD = D3D11_FLOAT32_MAX;

	// Create the texture sampler state.
	result = device->CreateSamplerState( &samplerDesc, &m_sampleState );
	if( FAILED( result ) )
	{
		return false;
	}

	// Setup the description of the dynamic pixel constant buffer that is in the pixel shader.
	pixelBufferDesc.Usage = D3D11_USAGE_DYNAMIC;
	pixelBufferDesc.ByteWidth = sizeof( PixelBufferType );
	pixelBufferDesc.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
	pixelBufferDesc.CPUAccessFlags = D3D11_CPU_ACCESS_WRITE;
	pixelBufferDesc.MiscFlags = 0;
	pixelBufferDesc.StructureByteStride = 0;

	// Create the pixel constant buffer pointer so we can access the pixel shader constant buffer from within this class.
	result = device->CreateBuffer( &pixelBufferDesc, NULL, &m_pixelBuffer );
	if( FAILED( result ) )
	{
		return false;
	}

	return true;
}


void FontShaderClass::ShutdownShader()
{
	// Release the pixel constant buffer.
	if( m_pixelBuffer )
	{
		m_pixelBuffer->Release();
		m_pixelBuffer = 0;
	}

	// Release the sampler state.
	if( m_sampleState )
	{
		m_sampleState->Release();
		m_sampleState = 0;
	}

	// Release the constant buffer.
	if( m_constantBuffer )
	{
		m_constantBuffer->Release();
		m_constantBuffer = 0;
	}

	// Release the layout.
	if( m_layout )
	{
		m_layout->Release();
		m_layout = 0;
	}

	// Release the pixel shader.
	if( m_pixelShader )
	{
		m_pixelShader->Release();
		m_pixelShader = 0;
	}

	// Release the vertex shader.
	if( m_vertexShader )
	{
		m_vertexShader->Release();
		m_vertexShader = 0;
	}

	return;
}


void FontShaderClass::OutputShaderErrorMessage( ID3D10Blob* errorMessage, HWND hwnd, WCHAR* shaderFilename )
{
	char* compileErrors;
	unsigned long bufferSize, i;
	ofstream fout;


	// Get a pointer to the error message text buffer.
	compileErrors = ( char* )( errorMessage->GetBufferPointer() );

	// Get the length of the message.
	bufferSize = errorMessage->GetBufferSize();

	// Open a file to write the error message to.
	fout.open( "shader-error.txt" );

	// Write out the error message.
	for( i = 0; i < bufferSize; i++ )
	{
		fout << compileErrors[ i ];
	}

	// Close the file.
	fout.close();

	// Release the error message.
	errorMessage->Release();
	errorMessage = 0;

	// Pop a message up on the screen to notify the user to check the text file for compile errors.
	MessageBox( hwnd, L"Error compiling shader.  Check shader-error.txt for message.", shaderFilename, MB_OK );

	return;
}


bool FontShaderClass::SetShaderParameters( ID3D11DeviceContext* deviceContext, const XMMATRIX& worldMatrix, const XMMATRIX& viewMatrix,
	const XMMATRIX& projectionMatrix, ID3D11ShaderResourceView* texture, const XMFLOAT4& pixelColor )
{
	HRESULT result;
	D3D11_MAPPED_SUBRESOURCE mappedResource;
	ConstantBufferType* dataPtr;
	unsigned int bufferNumber;
	PixelBufferType* dataPtr2;

	XMMATRIX worldMatrixCopy = worldMatrix;
	XMMATRIX viewMatrixCopy = viewMatrix;
	XMMATRIX projectionMatrixCopy = projectionMatrix;

	// Transpose the matrices to prepare them for the shader.
	worldMatrixCopy = XMMatrixTranspose( worldMatrix );
	viewMatrixCopy = XMMatrixTranspose( viewMatrix );
	projectionMatrixCopy = XMMatrixTranspose( projectionMatrix );
	
	// Lock the constant buffer so it can be written to.
	result = deviceContext->Map( m_constantBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource );
	if( FAILED( result ) )
	{
		return false;
	}

	// Get a pointer to the data in the constant buffer.
	dataPtr = ( ConstantBufferType* )mappedResource.pData;
	
	// Copy the matrices into the constant buffer.
	dataPtr->world = worldMatrixCopy;
	dataPtr->view = viewMatrixCopy;
	dataPtr->projection = projectionMatrixCopy;

	// Unlock the constant buffer.
	deviceContext->Unmap( m_constantBuffer, 0 );

	// Set the position of the constant buffer in the vertex shader.
	bufferNumber = 0;

	// Now set the constant buffer in the vertex shader with the updated values.
	deviceContext->VSSetConstantBuffers( bufferNumber, 1, &m_constantBuffer );

	// Set shader texture resource in the pixel shader.
	deviceContext->PSSetShaderResources( 0, 1, &texture );

	// Lock the pixel constant buffer so it can be written to.
	result = deviceContext->Map( m_pixelBuffer, 0, D3D11_MAP_WRITE_DISCARD, 0, &mappedResource );
	if( FAILED( result ) )
	{
		return false;
	}

	// Get a pointer to the data in the pixel constant buffer.
	dataPtr2 = ( PixelBufferType* )mappedResource.pData;

	// Copy the pixel color into the pixel constant buffer.
	dataPtr2->pixelColor = pixelColor;

	// Unlock the pixel constant buffer.
	deviceContext->Unmap( m_pixelBuffer, 0 );

	// Set the position of the pixel constant buffer in the pixel shader.
	bufferNumber = 0;

	// Now set the pixel constant buffer in the pixel shader with the updated value.
	deviceContext->PSSetConstantBuffers( bufferNumber, 1, &m_pixelBuffer );

	return true;
}


void FontShaderClass::RenderShader( ID3D11DeviceContext* deviceContext, int indexCount )
{
	// Set the vertex input layout.
	deviceContext->IASetInputLayout( m_layout );

	// Set the vertex and pixel shaders that will be used to render the triangles.
	deviceContext->VSSetShader( m_vertexShader, NULL, 0 );
	deviceContext->PSSetShader( m_pixelShader, NULL, 0 );

	// Set the sampler state in the pixel shader.
	deviceContext->PSSetSamplers( 0, 1, &m_sampleState );

	// Render the triangles.
	deviceContext->DrawIndexed( indexCount, 0, 0 );

	return;
}